Die edge grinding apparatus



p 1949- J. w. HEWITT, JR 2,482,001

DIE EDGE GRINDING APPARATUS Filed July 16, 1946 5 Sheets-Sheet l HIM Sept. 13, 1949. J. w. HEWITT, JR

DIE EDGE GRINDING APPARATUS Filed July 1a, 1946 5 Sheets-Sheet 2 FIG. 5.

gall/1 4 p 1949. J. w. HEWITT, JR 2,482,001

DIE EDGE GRINDING APPARATUS Filed July 16, 1946 5 Shets-Shee't 3 Sept. 13, 1949. J. w. HEWITT, JR 2,432,001

DIE EDGE GRINDING APPARATUS Filed July 1a, 1946 5 Sheets-Sheet 4 46 JOHN WHEW/TTJQ we e5 @ph 13, HQ4-9. HEWlTT, JR 2,482,9Q1

DIE EDGE GRINDING APPARATUS Filed July 16, 1946 v 5 Sheets-Sheet 5 JoH/v W. HEWITTJAZ "sh r e K Figure 6 is a section through the die blank-of" Patented Sept. 13 1949 UNITED STAT ES ATEN F CE manner: cnmpmdarrnna'rus John w. Hewitt, Jr Neenah, Wis. Applicationiluly is, 194 Serial No. 683,894

This invention relatesto the making of dies for rotary cutters of the type utilizing a die carrier roll and an anvil roll between which sheet or web 'cclaims. (can-241) material is fed for cutting out a plurality of Y articles shaped in accordance with the configuration of the dies. Rotary cutters of this character quiring highly skilled labor, to establish a cutting edge that is uniform over its entire extent.

Another object is to provide a method and apparatus for forming cutting lands of uniform taper on die blanks mounted in service position directly in a cutter roll on which they arejto be used.

A further object is to provide a novel method of edge-forming a rotary cutter die ina curved plane normal to the axis of the die.

Still another object is to provide an apparatus .for uniformly bevel grinding thecutting edge of "a die having its cutting edge disposed in a curved plane. Other ob'jectswill be apparent to those 1 skilled in the art.

The present disclosure constitutes an embodiment of method and apparatus by which the in- I vention is reduced to practice. It is tube understood that any desired changes in details of the structure and method may be made that are within the scope of the invention as claimed. Inthe drawings: v Figure 1 is an axial sectional view of a die blank prior to grinding in accordance with the invention;

' Figure 2 is an elevation of a cutter roll with.

die blanks mounted therein in service position preparatory to grinding;

Figure 3 is a section taken on the line 3-3 in Fi ure 2;

Figure 4 is a section trating the manner of circle grinding the die blanks as a step of the method;

Figure 5 is an axial section through enact the die blanks after it has been circle ground as similar to Figure '3 muse .of Figure 11;

Figure 5 but rotated QOdegrees relative thereto;

} Figure 7 is a fragmentary elevation illustratin a step in the grinding method by which excess -die blankmetal resulting from the circle grinding is removed by a work-guided grinding tool;

Figure 8 is a fragmentary. elevation similar to Figure '7 but with the grinding tool operating at a point rotated degrees relative to its Figure 7 position; i 1

Figure 9 is a fragmentary section througha completed die illustrating by dotted lines the extentof metal removed by the tool in its Figure 7 position;

, Figure 10 is a section similar to Figure 9 but rotated 90 degrees relative thereto, illustrating in dotted lines the extent of metal removed by the tool in its Figure 8 position;

. Figure 11 is an elevation of an assembly in .which the edge grinder tool is mounted for manual s hifting over the die edge being ground;

Figure 12 is a section taken on the line |2-|2 Figure. 13 is an elevation of an apparatus in which the edge grinder tool is automatically shifted over the die edge being ground and is at the same time automatically fed to the work; Figure 14 is a-bottom plan view of theapparatus shown in Figure 13; and

Figure .15 is a fragmentary elevation of a holder with a die blank therein in which the-cutting edge is less than a full circle.

As herein disclosed, a hollow die carrier roll 16 is utilized as the support for a plurality of die blanks l1 arranged as diametrically opposed pairs -;;in radial sockets l8 formed through the roll body. Locking screws l9 -threaded in radial sockets 20 engage retainer grooves 2| on the inner end portions of the die blanks to secure the blanks firmly in service position in the roll. Each die blank 5 bore 22 and an annular head 23, The head is comprises a cylindrical shank having an axial formed with a bevel 24-to provide a cutting edge or land-25- which occupies in its entirety a plane normal to the axis of the blank. Bearer rings I60. are secured on each end-of the roll for con- ..tact with an anvil roll (not shown) when the die S roll is placed in service. The-mounting of the die blanks in the die roll as shown in Figures 2 and 3 constitutes the first step in the method of this invention. At this stage, the cutting edges of the die blanks lie in planes tangential to the circumferenceoi a circle defined by the bearer rings. Inorder that the dies may function in service,

their cutting edges 25 must lie at all'points on the circumference of a'circle'that is equal in di- .function properly in service.

formed by the tool po'st reduction. fthreaded on "the upper end oithe tool serves to clamp the head block portion 33 against i the shoulder 35-, and the block is further locked to the tool post byset screw means 31.

3 ameter to the external diameter of the bearer rings l6a. This is accomplished in the second step of the method by circle grinding the die edges 25 as shown in Figures 4, 5 and 6. In this operation, the roll I6 is rotated to bring the die edges successively into operative engagement with a grinding surface 21, here shown as an oppositely rotated abrasive wheel, so positioned that the edges 25 will be ground oil on arcs which lie in the circum-ferenceof a circle of requisite diameter having: its axis perpendicular. to.;the axes of the die bores and coaxial with the roll I6.

4 stem 38 provides means by which the stem may be manually rotated to efiect axial movement of the motor 29 whereby to feed the tool 21 axially to its work. At a point diametrically opposite the screw feed assembly, the opposed edges of the split clamp sleeve are provided with integral ears 43 which extend with ample clearance laterally into a second longitudinal slot 44 in the head block 32. A bolt =45 in threaded engagement through the ears 43 enablesthe ears to be .fdrawdto'getherQto clamp the sleeve 30 firmly on The extent of metal removed at this stage is indi -3';-

cated in dotted lines in Figure 4. a v I At the conclusion of the circle grinding opera'-- tion the edges 25 are blunt. As a'result-of the i grinding, a land 25a, see Figures 5 and 6, is:

formed over the entire extent'of-eachedge. The

width of the land varies from a maximum; at diametrically opposite points in a plane at right angles to the axis of the roll it to aminimum jat'diametricallylopposite points in a plane roftated '90. degrees relative to the first plane. Figure 5 illustrates the maximum width of the land and Figure 6 the minimum. Unless the land is sharpened to providea cutting edge that is uniform throughout its extent, the die wouldiail to In this embodiment, the edge is sharpened to .003 or an inch with a tolerance of not more than .0005 of an inch at any point.

. Requisite' sharpening of the blunt land is effected in the third step of the method, by a bevel .grinding operation as shown in Figures 7 and 8. A tool post 26 is positionedin the bore of the'die I for'iree rotation and free axial movement therein.

This post has associated therewith, as shown in Figures 11 and 13, a bevel grinding tool 21, and carries a guide member 28 which extends radially from the post at a pointdiametrically opposite the bevel grinding tool. The guide 28, which is here shown as a rounded button or stud threaded into theshank of the tool post, seats on the circle 'grou nd cutting; edge of the die and follows the contour thereof asfthe post is rotated or oscillated to move the, grinding tool around the perimeter of the edge 25.

The bevel grinding tool 21 is disposed on an axis that is convergentto the axis of the tool post. As shown in Figures 11 and 13, it is driven by an electric motor 29 mounted in a split clamp sleeve. 36 by which it is tightly held. The sleeve and motor are axially movable as a unit in an appropriately formed bore 3lof a head block 3-2 that is'aiiixed' tothe upper end or the tool post. The block 32 has a lateral portionta-bored to engage over a reduced portion 34- at the upper end of the tool post and seat on the shoulder 35 A nut 36 post shank 'In the form of apparatus illustrated in Figure '39 integral with the head block 32 at thelower end of a guide slot 40 extending longitudinally the motor 29.

7 Manual oscillation or rotation of the tool post is passed entirely through the roll IS in the bores .iofa diametrically registering pair of die blanks.

The post 26 is reduced as at 260. immediately adjacent the tool 21 to provide adequate clearance for advancing movement of the tool.

1 After the die blanks are circle ground as previ- *ously' described, the roll 16 is mounted in a suitable support (not shown) and the tool'postis passed downwardly through a pair of vertically registering die blanks until the guldememb'er 28 "seats on: the circle ground edge or land 25. The

handle 46- is attached to the lower projecting end of the tool post, and the screw feed head 42 is .manipulated to bring thebevel grinding tool 21 againstthe bevelface 24 offthe die blank. When the motor 29 is set in operation, the abrasive tool 27 is rotated to grind otr metal from the bevel face "of the die. During operation of: the grindmg tool, the post-26 is oscillated .or rotated to move the tool around the perimeter of the die.

In the course of this i movement, the guide 28 follows the contour ofthe land on which it seats, and the post 26 thus moved axially to raise and lower the tool correspondingly. 'It' will be apparent that'as the tool moves down, it will bite deeper into'the bevel face of the die and remove a greater depth of metal than it does'as it rises. In this way the bevel-is groundoff to a uniform depth entirely: around theeutting edge so that the edge is of uniform sharpness over its entire extent, i Necessary axial feed of the grinding. tool :as the operation progresses'is effected by manipulation of the feed screw 42';

.Figures 13 and 14 illustrate an apparatusfor efiecting automaticcperation of the tool post .zrotating means andthe screwrfeed ,for the-bevel grindingtool. In this'embodiment or the invention, a bench 47 is provided with cradle uprights .48 which support the roll. I 6 with its mounted the blanks ll. An electric. motor 49 suitably supported beneath the; .bench drives a reduction gearing 50- which has a chain and sprocket connection 5| with a crank and; pitman assembly 52.;The'pitman 53zis operatively connected with one end of a rack bar 54 that is mounted for ;.horizontal,reciprocation in a guide 55 affixed to the underside of the-bench. The lower end'of the tool post 26, after it is positioned through the roll and die assembly, extends downwardly through a suitableaperture in the bench into operative engagement with the rack bar-54. At

'- its point of engagement with the rack bar, the

with the-rack. 7 0.

in the body of the block. The stem 38' has Qlug 4| is disposed in and guided by the slot 40.

integral with the motor clamp sleeve 30. The

operatinghead 42,0n the low r. en fnthe post is provided with pinion means 56in. mesh The upper portion of the tool post and the assembly of bevel grinding tool is substantially identical with the structure shownin Figure 11,

.' and the-.samereferencecharacters are employed to designate the same parts. In this'form of mtn invention. the oscillation of the tool: post is automatically efiected by the rack bar and pinion connection 54, 56, when the motor #9 is set in operation. At the same time, the bevel grinding tool 2! is driven by its motor 29 and is automatically fed against the die through the medium of a ratchet head 51 on the non-traveling bolt stem 38. As the tool post carrying the motor 29 is oscillated, the ratchet 51 has interval engagement with a pawl 58 mounted on a standard 59 secured to the bench. At each actuating engagement of the pawl and ratchet, the bolt 38 is rotated to advance the motor 29 axially for work engaging feed of the tool 21. A limit switch 60 on the tool post cooperates with a contact 6| carried by the motor 29 to open the motor circuit (not shown) when the tool 21 has reached a predetermined point in its advancing feed.

Although it is preferred that the die roll It be employed to hold the die blanks during the operations of circle grinding and bevel grinding, it is contemplated that these operations may be carried out on die blanks mounted in any suitable holder means. Furthermore, the die blanks may, as shown in Figure 15, comprise only segments oi a circle. In such cases, the segment IT to be finished is mounted in its holder IB and complemented by a dummy blank 62 of any material suitable as a filler to complete the die circle and hold the segment in position. The blank consisting of the assembled segment and filler is then processed by the circle grinding and bevel grinding operations previously described, after which the dummy blank is removed.

I claim:

1. Die edge forming means comprising in combination a support adapted to mount therein, an axially bored die blank having an annular bevel edge in the arc of a circle, a tool post rotatable and axially movable in the die b ank bore, a bevel grinding tool supported on said post for movement therewith, means for operat ng said tool against the bevel of the blank. and guide means on said post in contact with the cutting edge of the blank for shifting said post and grinding tool axially of the die in conformity with the profile of the cutting edge as the tool is moved circumferentially relative to the die.

2. Die edge forming means comprising in combination, a support adapted to mount therein a die having an axial bore, a tool post disposed in said bore for axial and rotary movement therein, said die having a bevel cutting edge of sinuous profile, a follower guide on said post in contact with the tip of said cutting edge for moving the tool post axially in the die bore in conformity with the profile of the cutting edge during rotation of said post relative to the die, a bevel grinding tool carried on the post for movement therewith as a unit, means for operating said tool against the bevel of the die, and means for rotating the tool post relative to the die.

3. Die edge forming means comprising in combination, a support adapted to mount therein a die having an axial bore, a tool post disposed in said bore for axial and rotary movement therein, said die having a cutting edge of sinuous profile, a guide member extending radially from said post in seated engagement on the tip of said cutting edge for moving the tool post axially in the die bore in conformity with the cutting edge profile during rotation of said post relative to the die, a bevel grinding tool supported on said post for movement therewith as a unit, said tool and guide member being diametrically opposed, means for operating said tool against the bevel of the die, and means for imparting rotary movement to the tool post.

4. Die edge grinding apparatus comprising a support, uprights thereon, a rotary die cutter roll positioned horizontally in said uprights and adapted to mount a pair of bevel edge dies radially in service position in said roll at diametrically opposed points, said dies having axial bores communicating through the roll interior, a tool post positioned vertically through the roll and dies and adapted for axial and rotary movement, a bevel grinding tool carried by the upper portion of said post for movement therewith as a unit, screw feed means on the tool post for advancing said tool against the bevel of a die, a fixed standard adjacent the tool post, cooperating pawl and ratchet elements on said standard and screw feed means for automatic operation of the screw feed during oscillation of the tool post, and means on said support in operative engagement with the lower end of said tool post for imparting oscillatory movement thereto.

5. In a die edge grinding apparatus, a tool post adapted for rotary and axial movement, an edge profile follower rigidly secured on said post and extending radially therefrom for bearing contact on the apex of a die edge, said post having a reduced portion opposite said follower, a grinding tool mounted on said post diametrically opposite said follower for bodily movement therewith, the axis of said tool being convergent to that of the post, and means for feeding said tool axially toward the reduced portion of the post.

6. Die edge forming means comprising in combination a support adapted to mount a die blank having a bevel edge portion in the arc of a circle, a tool post associated with said support for rotatable and axial movement relative to the die blank, a bevel grinding tool on said post and bodily movable therewith, means for operating said tool against the bevel of said blank, and guide means on said post bearing on the cutting edge of the blank to shift said post and grinding tool axially of the die blank in conformity with the profile of the cutting edge as the tool is rotated relative to the blank.

JOHN W. HEWITT, JR.

REFERENCES CITED The following references are of record in the file of this patent:

UNITED STATES PATENTS Number Name Date 1,591,288 Davis July 6, 1924 1,799,109 Lyne Mar. 31, 1931 1,972,761 Catching Sept. 4, 934 

